Whenever I try to add a 9-patch image to the \\drawable folder in my project, I get the same error:
\\drawable
ERROR: 9-patch image C:\\...\\res\\drawable\
For me the problem seems to be that I created the 9 patch myself. I thought it was enough to have a 1 px border on the left and top edges, but you need to make sure that the image has a 1 px border on each edge.